It is known that serious damages are caused by microorganisms in various fields. Thus, there has been urgently required to develop an effective and advantageous microbicide. For example, it is required in the field of agriculture to develop, for example, fungicides for controlling plant diseases caused by bacteria and molds, seed disinfectants and soil disinfectants. Further, there are serious problems in the field of technology. Namely, raw materials and products are contaminated or degraded with bacteria and molds, which lowers the commercial values of the products. Furthermore, the production process, facilities and environment are also contaminated therewith. It is urgently required to solve these problems.
Although some derivatives of isothiazolone are known [cf. JP-B-46 21240 (the term "JP-B" used herein means Japanese examined patent publication) corresponding to U.S Pat. No. 3,523,121 and J. Heterocyclic Chem., 8, 587 (1971)], the compound of the present invention has never been reported hitherto. In addition, every known compound is highly toxic to homeothermic animals and fishes, which significantly restricts the applications of the same.